I just thought a couple along the bottom of a tank would give a real look to it like leaves from a tree. All I know is the leaves have to be dry and clean of any debris. One article stated using oak, maple, stuff we have in our yards. I might collect some this fall and try it. They would have to be changed often but what the heck. Could be cool looking. I can't really come to terms of buying leaves, even almond. Most of is are trying to rid leaves, not pay to have them, lol.